Power conversion systems are employed in medium voltage motor drives and other applications in which electrical power is converted for driving electric motors or other loads. Such systems can include motor drives, starters, power conditioning equipment, etc., and are generally housed in cabinets to protect the system components from dirt or other contaminants as well as to prevent exposure of operating personnel to high voltages and currents present inside the cabinet. In this respect, medium voltage motor drives typically include transformers, contactors, switches, starter components, and other high power electronic devices that may include exposed terminals carrying tens or hundreds of amps and which may be at hundreds or even thousands of volts potential with respect to ground. Closed cabinetry thus serves to prevent inadvertent contact by operators or other personnel with live components of motor drives, starters, and other power conversion systems during normal system operation. Often, however, maintenance must be performed on system components, and the cabinet enclosure must be opened to allow access for observing, testing, repairing and/or replacing system devices. In this situation, it is desirable to both prevent contact with live components and to allow easy access to devices being maintained. Accordingly, most cabinets include removable access panels or hinged doors by which maintenance personnel may access the interior of the cabinet. However, certain components such as high power contactors, transformers, capacitors, etc., are heavy and/or bulky, whereby external carts or portable supports must be positioned on the outside of the cabinet near the access panel or door to receive the components as they are withdrawn from the cabinet. Positioning such supporting structures near the access portals often impedes access to the cabinet interior, whereby service personnel must lean over the cart to reach the component being removed. In addition to such accessibility issues, switches, interlocks, and other mechanical safety systems must be provided in order to ensure that the devices being serviced are powered down prior to physical access by maintenance personnel. Thus, there is a continuing need for apparatus and methods by which power conversion system components can be safely disconnected from electrical power and withdrawn from cabinets.